Epidemiological characteristics of human avian influenza A (H7N9) virus infection in China.

Ruiqi Ren; Lei Zhou; Nijuan Xiang; Bo Liu; Jian Zhao; Xingyi Geng; Yali Wang; Chao LI; Yong Lyu; Fuqiang Yang; Ming Yang; Haitian Sui; Xu Huang; Ling Meng; Zhiheng Hong; Wenxiao TU; Yang Cao; Leilei LI; Fan Ding; Zhe Wang; Rui Wang; Jianyi Yao; Yongjun Gao; Lianmei Jin; Yanping Zhang; Daxin NI; Qun LI; Zijian Feng

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Epidemiological characteristics of human avian influenza A (H7N9) virus infection in China.

Author: Ruiqi REN ¹ ; Lei ZHOU ¹ ; Nijuan XIANG ¹ ; Bo LIU ¹ ; Jian ZHAO ¹ ; Xingyi GENG ² ; Yali WANG ¹ ; Chao LI ³ ; Yong LYU ⁴ ; Fuqiang YANG ⁵ ; Ming YANG ⁶ ; Haitian SUI ¹ ; Xu HUANG ¹ ; Ling MENG ¹ ; Zhiheng HONG ¹ ; Wenxiao TU ¹ ; Yang CAO ¹ ; Leilei LI ¹ ; Fan DING ¹ ; Zhe WANG ¹ ; Rui WANG ¹ ; Jianyi YAO ¹ ; Yongjun GAO ¹ ; Lianmei JIN ¹ ; Yanping ZHANG ¹ ; Daxin NI ¹ ; Qun LI ¹ ; Zijian FENG ¹
Author Information

1. Public Health Emergency Center of Chinese Center for Disease Control and Prevention (CDC), Beijing 102206, China.
2. Department of Public Health Emergency, Jinan City CDC.
3. Institute of Prevention and Control for Communicable Disease, Tianjin CDC.
4. Department of Prevention and Control for Communicable Disease, Liu'an City CDC.
5. Public Health Emergency Center of Jiangxi Provincial CDC.
6. Public Health Emergency Center of Xuancheng City CDC.
Publication Type:Journal Article
MeSH: Adaptation, Psychological; Aged; Animals; China; epidemiology; Demography; Environmental Pollution; Female; Humans; Influenza A Virus, H7N9 Subtype; Influenza, Human; epidemiology; prevention & control; transmission; Male; Meat; Poultry; Research Design
From: Chinese Journal of Epidemiology 2014;35(12):1362-1365
CountryChina
Language:Chinese
Abstract:
OBJECTIVETo investigate the epidemiological characteristics of human infections with avian influenza A (H7N9) in China and to provide scientific evidence for the adjustment of preventive strategy and control measures.
METHODSDemographic and epidemiologic information on human cases were collected from both reported data of field epidemiological investigation and the reporting system for infectious diseases.
RESULTSA total of 433 cases including 163 deaths were reported in mainland China before June 4, 2014. Two obvious epidemic peaks were noticed, in March to April, 2013 and January to February, 2014. Confirmed cases emerged in 14 areas of China. Five provinces, including Zhejiang, Guangdong, Jiangsu, Shanghai, and Hunan, reported about 85% of the total cases. Median age of the confirmed cases was 58 years (range, 1-91), with 70% as males. Of the 418 cases with available data, 87% had ever exposed to live poultry or contaminated environments. 14 clusters were identified but human to human transmission could not be ruled out in 9 clusters.
CONCLUSIONHuman infections with avian influenza A (H7N9) virus showed the characteristics of obvious seasonal distribution, with certain regional clusters. The majority of confirmed cases were among the elderly, with more males seen than the females. Data showed that main source of infection was live poultry and the live poultry market had played a significant role in the transmission of the virus.